Weathercatch: Last week's wild weather closed highways and schools – what happened and why

<p><p>It’s OK if you thoroughly disliked winter last week. Maybe you even disdained it.</p></p><p><p>The region got hit with everything from heavy snow, strong winds and soaking rain to freezing rain, slush, puddles and then, ice.</p></p><p><p>And it all happened in a few days.</p></p><p><p>The wild weather pattern we experienced was largely spurred by an atmospheric river that made landfall in the Pacific Northwest late evening Jan. 5. The powerful jet of high-altitude moisture went on to produce record-setting precipitation and a multitude of challenging weather conditions statewide.</p></p><p><p>Wenatchee shattered an all-time snowfall record in a 24-period, when Jan. 5-6 accumulations topped out at 23.3 inches, according to the National Weather Service in Spokane. The city’s previous record of 16.5 inches was set in December 1971. Meanwhile, the coastal town of Hoquiam experienced its wettest day on Jan. 6, with 5.78 inches of rainfall. On that same date, famously rainy Seattle recorded its seventh-wettest January day , with 2 inches recorded at the Seattle-Tacoma International Airport.</p></p><p><p>Also, a combination of snow and rain, falling trees and avalanche danger closed four of the state’s mountain passes, including a portion of Interstate 90 over Snoqualmie Pass, the main arterial linking Eastern and Western Washington. Additionally, river flood waters closed a 20-mile section of Interstate 5 near Chehalis.</p></p><p><p>Locally, Spokane got 5.3 inches of snow on Jan. 6, making it the city’s largest snowfall of winter so far. That night, falling snow turned to freezing rain, followed by a straight 0.37 inches of rainfall the next day when the temperature climbed to 41 degrees. Likewise, communities across the Palouse received 6-8 inches of snow on Jan. 6, followed by rain as temperatures rose and winds intensified on Friday.</p></p><p><p>That afternoon, the temperature in Yakima climbed to 50 degrees. Wenatchee – in less than one hour – went from 30 degrees and calm to 42 degrees and 22 mph winds, according to the weather service.</p></p><p><p>The highest reported wind gusts included 48 mph in Spokane, 49 mph in Wenatchee and as high as 58 mph at the Moscow-Pullman Airport.</p></p><p><p>Not surprisingly, the resulting melting snow turned to piles of slush and puddles of water. Gutters dripped and slabs of wet snow slid off roofs.</p></p><p><p>Then, overnight, temperatures dropped and the world around us refroze. When we awoke on Saturday, snow berms had turned cement-like and many and roads were glazed with ice. But hey, at least the sun was shining.</p></p><p><p>The atmospheric river responsible for the surge in moisture and strong winds was rated a Category 4 out of 5 as it barreled over the Pacific Ocean toward the West Coast, according to the Center for Western Weather and Water Extremes’ rating scale.</p></p><p><p>Originating west of Hawaii, it carried warm, moisture-rich air that fell as rain and snow after it made landfall and traveled east across Washington and Oregon.</p></p><p><p>With the warm-up came a surge of southwesterly winds.</p></p><p><p>The system fizzled out by last weekend, when a ridge of high pressure off the coast helped turn weather conditions to cold, quiet and dry – albeit icy. Those conditions held through Monday of this week, followed by a light wintry mix and freezing rain in the Spokane area on Tuesday and Wednesday. Barring the arrival of another atmospheric river this weekend, it should be mostly dry with highs close to 40 degrees and lows near 30, along with some clouds and patchy fog.</p></p>